Interactive Education System With Physiological Modeling

ABSTRACT

Patient simulator systems for teaching patient care are provided. In some instances, the patient simulator systems include a patient body comprising one or more simulated body portions. Generally, the patient simulator systems of the present disclosure provide physiological modeling. In one embodiment, the patient simulator includes a maternal simulator comprising a maternal circulatory model, a maternal cardiac ischemia model, and a maternal respiratory model and a fetal simulator comprising a fetal circulatory model, a fetal cardiac ischemia model, and a fetal central nervous system model. A controller in communication with the maternal and fetal simulators coordinates parameters of the maternal circulatory model, the maternal cardiac ischemia model, the maternal respiratory model, the fetal circulatory model, the fetal cardiac ischemia model, and the fetal central nervous system model to simulate physiological characteristics of a natural mother and fetus. Methods of utilizing the patient simulator systems are also provided.

BACKGROUND

The present disclosure relates generally to interactive educationsystems for teaching patient care. While it is desirable to trainmedical personnel in patient care protocols before allowing contact withreal patients, textbooks and flash cards lack the important benefits tostudents that can be attained from hands-on practice. On the other hand,allowing inexperienced students to perform medical procedures on actualpatients that would allow for the hands-on practice cannot be considereda viable alternative because of the inherent risk to the patient.Because of these factors patient care education has often been taughtusing medical instruments to perform patient care activity on asimulator, such as a manikin. Examples of such simulators include thosedisclosed in U.S. patent application Ser. No. 11/952,559, U.S. patentapplication Ser. No. 11/952,606, U.S. patent application Ser. No.11/952,636, U.S. patent application Ser. No. 11/952,669, U.S. patentapplication Ser. No. 11/952,698, U.S. Pat. No. 7,114,954, U.S. Pat. No.6,758,676, U.S. Pat. No. 6,503,087, U.S. Pat. No. 6,527,558, U.S. Pat.No. 6,443,735, U.S. Pat. No. 6,193,519, and U.S. Pat. No. 5,853,292,each herein incorporated by reference in its entirety.

While these simulators have been adequate in many respects, they havenot been adequate in all respects. Therefore, what is needed is aninteractive education system for use in conducting patient care trainingsessions that is even more realistic and/or includes additionalsimulated features.

SUMMARY

The present disclosure provides interactive education systems,apparatus, components, and methods for teaching patient care thatinclude physiological modeling.

In one embodiment, a system for teaching patient care is provided. Thesystem includes a maternal simulator and a fetal simulator. The maternalsimulator includes a maternal circulatory model, a maternal cardiacischemia model, and a maternal respiratory model, while the fetalsimulator includes a fetal circulatory model, a fetal cardiac ischemiamodel, and a fetal central nervous system model. The fetal simulator isin communication with the maternal simulator. Further, a controller isin communication with each of the maternal simulator and the fetalsimulator. The controller coordinates parameters of the maternalcirculatory model, the maternal cardiac ischemia model, the maternalrespiratory model, the fetal circulatory model, the fetal cardiacischemia model, and the fetal central nervous system model to simulatephysiological characteristics of a natural mother and fetus.

In some instances, the maternal circulatory model is a multi-compartmentcirculatory model that includes a simulated uterus. The maternalcirculatory model further includes a simulated right atrium, a simulatedright ventricle, a simulated left atrium, and a simulated left ventriclein some embodiments. The maternal circulatory model includes variouscombinations of the anatomical features of the natural circulatorysystem. Generally, any combination of the anatomical features of thenatural circulatory system may be included in the maternal circulatorymodel. As described below, in some instances the maternal circulatorymodel is an 19-compartment circulatory model. In some instances, thematernal ischemia model includes a simulated aorta and a simulatedcoronary artery. The maternal respiratory model includes a simulatedright lung and a simulated left lung, in some embodiments. Therespiratory model further includes dead space (e.g., airway and alveoli)in some instances. In some instances, the maternal simulator furtherincludes a maternal cardiac dipole model. In that regard, the maternalcardiac dipole model generates 12-lead ECG waves for four heart chambersof the maternal circulatory model in some instances. The maternalcardiac dipole model further generates a contraction profile thatincludes timing and contractility of each of the four heart chambersduring a contraction, in some embodiments.

In some instances, the fetal circulatory model is a multi-compartmentcirculatory model that includes a simulated placenta. The fetalcirculatory model further includes a simulated right atrium, a simulatedright ventricle, a simulated left atrium, and a simulated left ventriclein some embodiments. The maternal circulatory model includes variouscombinations of the anatomical features of the natural circulatorysystem. Generally, any combination of the anatomical features of thenatural circulatory system may be included in the fetal circulatorymodel. As described below, in some instances the fetal circulatory modelis an 18-compartment circulatory model. In some instances, the fetalischemia model includes a simulated aorta and a simulated coronaryartery. In some instances, the maternal circulatory model and the fetalcirculatory model are connected to one another. For example, in someembodiments the maternal circulatory model includes a simulated uterusand the fetal circulatory model includes a simulated placenta such thatthe simulated placenta is connected to the simulated uterus. Further, insome instances the maternal simulator includes a mechanism configured totranslate and rotate the fetal simulator relative to maternal simulatorto simulate a birth.

In some embodiments, the controller includes a processor programmed tocoordinate parameters of the maternal circulatory model, the maternalcardiac ischemia model, the maternal respiratory model, the fetalcirculatory model, the fetal cardiac ischemia model, and the fetalcentral nervous system model based on a desired physiological scenario.In that regard, the controller is positioned remote from the maternalsimulator in some instances. For example, the controller is positionedwithin a computing device that is in communication with the maternalsimulator and/or the fetal simulator in some embodiments. The desiredphysiological scenario is selectable by a user through a user interfacein some instances. The desired physiological scenario is selected fromscenarios such as maternal bleeding, maternal uterine rupture, maternalapnea, maternal VFib, maternal VTach, fetal bleeding, fetal cordcompression, and/or other physiological scenarios.

In some embodiments, the system further includes a neonatal simulatorfor use in post birth situations. The neonatal simulator includes aneonatal circulatory model, a neonatal cardiac ischemia model, and aneonatal respiratory model. In some instances, the controller is incommunication with the neonatal simulator and configured to coordinateparameters of the neonatal circulatory model, the neonatal cardiacischemia model, and the neonatal respiratory model to simulatephysiological characteristics of a newborn. In that regard, theparameters of the neonatal circulatory model and the neonatal cardiacischemia model are at least partially based upon the parameters of thefetal circulatory model and the fetal cardiac ischemia model in someinstances.

In another embodiment, an apparatus with physiological modeling isprovided. In that regard, the apparatus includes a patient simulatorhaving a patient body comprising one or more simulated body portions,including at least a simulated circulatory system and a simulatedrespiratory system. The apparatus also includes a controller incommunication with the patient simulator. The controller is configuredto coordinate parameters of the simulated circulatory system and thesimulated respiratory system to simulate physiological characteristicsassociated with a desired physiological scenario. The controllerdetermines the parameters of the simulated circulatory system and thesimulated respiratory system for the desired physiological scenariobased on a circulatory model and a respiratory model for the patientsimulator.

In some instances, the circulatory model is a multi-compartmentcirculatory model including a simulated right atrium, a simulated rightventricle, a simulated left atrium, and a simulated left ventricle. Thecirculatory model includes various combinations of the anatomicalfeatures of the natural circulatory system. Generally, any combinationof the anatomical features of the natural circulatory system may beincluded in the circulatory model. As described below, in some instancesthe circulatory model is a 18-compartment circulatory model. In someinstances, the patient simulator is a maternal simulator and thecirculatory model further includes a simulated uterus. The respiratorymodel includes a simulated right lung and a simulated left lung. In someinstances, the respiratory model further includes dead space. In someembodiments, the controller determines the parameters of the simulatedcirculatory system for the desired physiological scenario at leastpartially based on an ischemia model for the patient simulator, wherethe ischemia model includes a simulated aorta and a simulated coronaryartery. In some embodiments, the patient simulator is configured togenerate 12-lead ECG waves and contraction profiles for a heart of thesimulated circulatory system. In that regard, the controller controlsthe 12-lead ECG waves and contraction profiles generated by the patientsimulator. The controller determines values for the 12-lead ECG wavesand the contraction profiles based on a cardiac dipole model in someembodiments.

In some instances, the patient body is sized and shaped to simulate anewborn. In that regard, the parameters of the simulated circulatorysystem are at least partially based on physiological characteristics ofa fetus associated with the newborn in some instances. For example, insome embodiments, the fetus associated with the newborn is the patientsimulator prior to a birthing simulation, and the newborn is the patientsimulator after the birthing simulation.

In another embodiment, methods of teaching patient care are provided. Inone embodiment, the method includes providing a maternal simulatorcomprising a simulated maternal circulatory system and a simulatedmaternal respiratory system; providing a fetal simulator for use withthe maternal simulator, the fetal simulator comprising a simulated fetalcirculatory system; controlling one or more parameters of the simulatedmaternal circulatory system and simulated maternal respiratory systembased on a maternal circulatory model, a maternal cardiac ischemiamodel, and a maternal respiratory model; and controlling one or moreparameters of the simulated fetal circulatory system based on a fetalcirculatory model, a fetal cardiac ischemia model, and a fetal centralnervous system model. The parameters of the simulated maternalcirculatory system, the simulated maternal respiratory system, and thesimulated fetal circulatory system are coordinated to simulatephysiological characteristics of a natural mother and fetus for adesired physiological scenario.

In some instances, the controlling of the one or more parameters of thesimulated maternal circulatory system is further based on a maternalcardiac dipole model. The one or more controlled parameters of thesimulated maternal circulatory system include one or more of a maternalblood pressure, a maternal heart rate, a maternal cardiac rhythm, and/orother parameters. The one or more controlled parameters of the simulatedfetal circulatory system include a fetal heart rate and/or otherparameters.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present disclosure will becomeapparent in the following detailed description of illustrativeembodiments with reference to the accompanying of drawings, of which:

FIG. 1 is a diagrammatic schematic view of an arrangement incorporatingaspects of the present disclosure.

FIG. 2 is a diagrammatic schematic view of a maternal circulatory modelof the arrangement of FIG. 1 according to one embodiment of the presentdisclosure.

FIG. 3 is a diagrammatic schematic view of a fetal circulatory model ofthe arrangement of FIG. 1 according to one embodiment of the presentdisclosure.

FIG. 4 is a diagrammatic schematic view of a neonatal circulatory modelof the arrangement of FIG. 1 according to one embodiment of the presentdisclosure.

FIG. 5 is a diagrammatic schematic view of a respiratory model of thearrangement of FIG. 1 according to one embodiment of the presentdisclosure.

FIG. 6 is a screen shot of a user interface according to another aspectof the present disclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the disclosure is intended. Any alterations and furthermodifications in the described devices, instruments, methods, and anyfurther application of the principles of the disclosure as describedherein are contemplated as would normally occur to one skilled in theart to which the disclosure relates. In particular, it is fullycontemplated that the features, components, and/or steps described withrespect to one embodiment may be combined with the features, components,and/or steps described with respect to other embodiments of the presentdisclosure.

One of the aims of healthcare simulation is to establish a teachingenvironment that closely mimics key clinical cases in a reproduciblemanner. The introduction of high fidelity tetherless simulators, such asthose available from Gaumard Scientific Company, Inc., over the past fewyears has proven to be a significant advance in creating realisticteaching environments. The concepts of the present disclosure take thesimulators to another level of realism by introducing physiologicalmodeling into the simulators. In particular, the present disclosureprovides physiological systems that are modeled on concurrentdifferential equations to provide autonomous or semi autonomous controlof the simulators' vital signs. In that regard, in many instances thephysiological modeling is executed without the need for substantialinput or direction from the facilitator or user in control of thesimulator. Rather, in many instances, the facilitator or user in controlof the simulator need only actuate a particular scenario through auser-interface (e.g., clicking on a simulated button for the particularphysiological scenario on a display associated with a computing device)and the physiological models will automatically control the vital signsof the simulators based on the selected scenario and/or the user'sinteraction with the simulators (e.g., treatments applied to thesimulator(s)). In this manner, the present disclosure provides improvedmedical simulation teaching environments. In some instances, thephysiological modeling of the present disclosure is particularly focusedon the physiological interaction between a mother and a fetus and,subsequently, the newborn. As the health of the mother, fetus, andnewborn are interconnected, a more realistic simulation teachingenvironment will simulate these interactions in a realistic manner. Thepresent disclosure provides such realistic interaction between thephysiological characteristics of the mother and fetus and, in someinstances, a corresponding newborn by controlling the physiologicalcharacteristics of each of the simulators based on physiological modelsrelating the physiological characteristics of the simulators to oneanother.

Referring to FIG. 1, shown therein is an arrangement 100 illustratingaspects of the present disclosure. In particular, FIG. 1 is adiagrammatic schematic view of the arrangement 100. In that regard, thearrangement 100 includes a pregnancy model 102 that includes a maternalmodel 104 and a fetal model 106, along with a neonatal model 108. Insome instances, aspects of the present disclosure are configured for usewith the simulators and the related features disclosed in U.S. patentapplication Ser. No. 11/952,559, U.S. patent application Ser. No.11/952,606, U.S. patent application Ser. No. 11/952,636, U.S. patentapplication Ser. No. 11/952,669, U.S. patent application Ser. No.11/952,698, U.S. Pat. No. 7,114,954, U.S. Pat. No. 6,758,676, U.S. Pat.No. 6,503,087, U.S. Pat. No. 6,527,558, U.S. Pat. No. 6,443,735, U.S.Pat. No. 6,193,519, and U.S. Pat. No. 5,853,292, each hereinincorporated by reference in its entirety. For example, in someinstances, one or more of the physiological models of the presentdisclosure are incorporated into the simulators, controllers, software,and/or user interfaces disclosed in these patents and applications. Inthat regard, the maternal model 104 is associated with a maternalsimulator in some instances. Similarly, the fetal model 106 and/or theneonatal model 108 are associated with a fetal simulator and a neonatalsimulator, respectively, in some instances.

As discussed in greater detail below, the maternal model 104, the fetalmodel 106, and/or the neonatal model 108 are utilized to control therespective simulated physiological characteristics of the simulators inorder to simulate the physiological characteristics associated with oneor more birthing scenarios. In that regard, the vital signs andphysiological characteristics generated by the physiological models arereadable or measurable on the simulators using standard medicalequipment in some instances. In addition, the vital signs andphysiological characteristics are visible on associated monitors and/ora user-interface control program in some embodiments.

Generally, two information pathways connect the maternal model 104, thefetal model 106, and the neonatal model 108. A first information pathwaycoordinates the interactions between maternal model 104 and the fetalmodel 106 (e.g., blood flows, gas exchanges, core temperature, etc.),while a second information pathway passes off the model parameters fromthe fetal model 106 to the neonatal model 108 at the end of a laborscenario. In that regard, the neonatal model 108 corresponds to thefetal model 106 after birth. Accordingly, in some instances the fetalmodel 106 and the neonatal model 108 are utilized to control thephysiological characteristics of a single simulator or manikin. In otherinstances, the fetal model 106 is utilized to control a fetalsimulator/manikin, while the neonatal model 108 is utilized to controlthe physiological characteristics of a neonatal simulator/manikin thatis separate from the fetal simulator/manikin. In such instances, themodel parameters of the neonatal model 108 are coordinated with those ofthe fetal model 106 such that the neonatal simulator/manikin exhibitsphysiological characteristics consistent with those of the fetalsimulator/manikin used in a labor scenario. Accordingly, in someembodiments the neonatal model 108 and associated neonatalsimulator/manikin are particularly suited for use in post-birthsimulations.

Referring now to FIG. 2, shown therein is a diagrammatic schematic viewof a maternal circulatory model 110 that makes up at least a portion ofthe maternal model 104 of the pregnancy model 102 of the arrangement 100illustrated in FIG. 1, according to one embodiment of the presentdisclosure. Generally, the maternal circulatory model 110 is amulti-compartment circulatory model that includes simulated anatomicalfeatures of the natural circulatory system. In the illustratedembodiment of FIG. 2, the maternal circulatory model is an19-compartment circulatory model. However, in other instances, thematernal circulatory model 110 includes other combinations of theanatomical features of the natural circulatory system. Generally, anycombination of the anatomical features of the natural circulatory systemmay be included in the maternal circulatory model 110. The particularcombination of anatomical features utilized in the maternal circulatorymodel 110 of FIG. 2 will now be discussed in greater detail.

As shown, the maternal circulatory model 110 includes a right atrium112, a right ventricle 114, and a pulmonary artery 116. The maternalcirculatory model 110 also includes respiratory features 118. In theillustrated embodiment, the respiratory features 118 include left andright lungs and a shunt. In some instances, characteristics of therespiratory features 118 are at least partially determined by arespiratory model, such as the respiratory model discussed below withrespect to FIG. 5. Referring again to FIG. 2, the maternal circulatorymodel also includes a pulmonary vein 120, a left atrium 122, a leftventricle 124, and an aorta 126. As shown, the aorta 126 is connected toa coronary artery 128 that leads to the right atrium 112. In someinstances, the aorta 126, the coronary artery 128, and the right atrium112 form a maternal ischemia model. In general, the ischemia model isutilized to calculate characteristics of the components of the maternalcirculatory model, including such things as the contractility of thefour heart chambers, an ECG output of the maternal model, and/or otherischemia-determinant characteristics of the maternal circulatory model.In some instances, the maternal model includes a maternal cardiac dipolemodel based on these characteristics that generates 12-lead ECG wavesfor four heart chambers of the maternal circulatory model and alsogenerates a contraction profile that includes timing and contractilityof each of the four heart chambers during a contraction.

The aorta 126 of the maternal circulatory model 110 is also connected toa descending aorta 130 that leads to arterioles 132. The arterioles 132lead to fat 134, vein-rich tissue 136, muscle 138, and a uterus 140.Generally, the fat 134, vein-rich tissue 136, muscle 138, and uterus 140represent the tissues and organs of the mother and their correspondingeffects on the maternal circulatory system. However, any combinationand/or groupings of tissues and organs of the mother may be utilized inother embodiments to account for the effects of the tissues and organsof the mother on the maternal circulatory system. The fat 134, vein-richtissue 136, muscle 138, and uterus 140 lead to venules 142. The venules142 lead to a vena cava 144 that returns back to the right atrium 112.Generally, the right atrium 112, right ventricle 114, pulmonary artery116, respiratory features 118, pulmonary vein 120, left atrium 122, leftventricle 124, aorta 126, coronary artery 128, descending aorta 130,arterioles 132, fat 134, vein rich tissue 136, muscle 138, uterus 140,venules 142, and vena cava 144 are interconnected in a manner simulatingthe interactions of the corresponding anatomical features of the naturalcirculatory system in order to define the maternal circulatory model110.

As shown, the uterus 140 is connected to a placenta 146 of the fetalmodel 106. In that regard, the connection between the uterus 140 and theplacenta 146 facilitates an exchange 148 between the maternal model 104and the fetal model 106. The exchange 148 includes a transfer 150 fromthe uterus 140 to the placenta 146 and a transfer 152 from the placenta146 back to the uterus 140. Generally, the transfer 150 simulates thesending of oxygen rich blood and nutrients to the fetus through theplacenta, while the transfer 152 simulates the sending of blood withincreased amounts of carbon dioxide from the fetus back to the motherthrough the placenta and into the uterus.

Referring now to FIG. 3, shown therein is a diagrammatic schematic viewof a fetal circulatory model 160 that makes up at least a portion of thefetal model 106 of the pregnancy model 102 of the arrangement 100illustrated in FIG. 1, according to one embodiment of the presentdisclosure. Generally, the fetal circulatory model 160 is amulti-compartment circulatory model that includes simulated anatomicalfeatures of the natural circulatory system of a fetus. In theillustrated embodiment of FIG. 3, the fetal circulatory model 160 is an18-compartment circulatory model. In that regard, the left and rightlungs of the fetal simulator are combined into a single compartment insome instances. However, in other instances, the fetal circulatory model160 includes other combinations of the anatomical features of thenatural circulatory system. Generally, any combination of the anatomicalfeatures of the natural circulatory system may be included in the fetalcirculatory model 160. The particular combination of anatomical featuresutilized in the fetal circulatory model 160 of FIG. 3 will now bediscussed in greater detail.

As shown, the fetal circulatory model 160 includes a right atrium 162, aright ventricle 164, and a pulmonary artery 166. The fetal circulatorymodel 160 also includes lungs 168. However, as the fetus is not yetbreathing the lungs 168 do not operate according to normal respiratoryfunctions. Accordingly, whereas the respiratory features 118 of thematernal circulatory model 110, for example, may operate according to arespiratory model, such as the respiratory model described below inconjunction with FIG. 5, the lungs 168 of the fetal circulatory model160 do not follow such respiratory models based on respiratory featuresthat are being utilized for breathing. In that regard, the lungs 168 donot oxygenize the blood, but rather utilize some of the oxygen in theblood in order to maintain the health of the lungs.

Referring again to FIG. 3, the fetal circulatory model 160 also includesa pulmonary vein 170, a left atrium 172, a left ventricle 174, and anaorta 176. As shown, the aorta 176 is connected to a coronary artery 178that leads to the right atrium 172. In some instances, the aorta 176,the coronary artery 178, and the right atrium 172 form a fetal ischemiamodel. In general, the fetal ischemia model is utilized to calculatecharacteristics of the components of the fetal circulatory model. Insome instances, the fetal ischemia model is determines suchcharacteristics as the contractility of the four heart chambers, an ECGoutput of the fetal model, and/or other ischemia-determinantcharacteristics of the fetal circulatory model.

The aorta 166 of the fetal circulatory model 160 is also connected to adescending aorta 180 that leads to arterioles 182. The arterioles 182lead to fat 184, vein-rich tissue 186, muscle 188, and the placenta 146.Generally, the fat 184, vein-rich tissue 186, muscle 188, and placenta146 represent the tissues and organs of the fetus and theircorresponding effects on the fetal circulatory system. However, anycombination and/or groupings of tissues and organs of the fetus may beutilized in other embodiments to account for the effects of the tissuesand organs of the fetus on the fetal circulatory system. The fat 184,vein-rich tissue 186, muscle 188, and placenta 146 lead to venules 190.The venules 190 lead to a vena cava 192 that returns back to the rightatrium 162. The fetal circulatory model 160 further includes a shunt 194that is in communication with the pulmonary artery 166, as shown. Inthat regard, the fetal circulatory model 160 also includes a pluralityof shunt flows as illustrated by flows 196, 198, and 200. Specifically,flow 196 illustrates the shunt flow between the shunt 194 and a fetalcentral nervous system model 202. Flow 198 illustrates the shunt flowbetween the right atrium 162 and the left atrium 172. Finally, flow 200illustrates the shunt flow between the placenta 146 and the vena cava192.

As mentioned above, the fetal circulatory model 160 includes a fetalcentral nervous system model 202. The connection between the fetalcirculatory model 160 and the fetal central nervous system model 202facilitates an exchange 204 between the circulatory system and thenervous system of the fetus. In particular, the exchange 204 includes atransfer 206 simulating the sending oxygen rich blood from thecirculatory system to the central nervous system and a transfer 208simulating the sending of blood with increased amounts of carbon dioxidefrom the central nervous system back into the circulatory system. Theamount of oxygen utilized by the fetal central nervous system model 202is influenced by both maternal conditions (e.g., oxygen partialpressure, cardiac output, uterine activity) and fetal conditions (e.g.,fetal movement, oxygen level, cord compression, head compression,hemorrhage). Accordingly, the fetal central nervous system model 202 hasa direct influence on characteristics of the fetal circulatory model,including fetal heart rate and oxygen level.

Generally, the right atrium 162, right ventricle 164, pulmonary artery166, lungs 168, pulmonary vein 170, left atrium 172, left ventricle 174,aorta 176, coronary artery 178, descending aorta 180, arterioles 182,fat 184, vein rich tissue 186, muscle 188, placenta 146, venules 190,vena cava 192, shunt 194, and central nervous system 202 areinterconnected in a manner simulating the interactions of thecorresponding anatomical features of the natural circulatory system inorder to define the fetal circulatory model 160.

As noted above, the connection between the uterus 140 and the placenta146 facilitates the exchange 148 between the maternal model 104 and thefetal model 106. The exchange 148 includes the transfer 150 from theuterus 140 to the placenta 146 and the transfer 152 from the placenta146 back to the uterus 140. Generally, the transfer 150 simulates thesending of oxygen rich blood and nutrients to the fetus through theplacenta, while the transfer 152 simulates the sending of blood withincreased amounts of carbon dioxide from the fetus back to the motherthrough the placenta and into the uterus. Accordingly, the exchange 148is utilized to link the circulatory models 110, 160 of the maternal andfetal models 104, 106 in order to define the overall circulatory modelfor the pregnancy model 102. Particular interactions and relationshipsbetween the maternal model 104 and the fetal model 106, including thecirculatory models 110, 160, are discussed below with respect to someexemplary physiological scenarios.

Referring now to FIG. 4, shown therein is a diagrammatic schematic viewof a neonatal circulatory model 210 that makes up at least a portion ofthe neonatal model 108 of the arrangement 100 illustrated in FIG. 1,according to one embodiment of the present disclosure. Generally, theneonatal circulatory model 210 is a multi-compartment circulatory modelthat includes simulated anatomical features of the natural circulatorysystem. In the illustrated embodiment of FIG. 4, the neonatalcirculatory model is a 18-compartment circulatory model. However, inother instances, the neonatal circulatory model 210 includes othercombinations of the anatomical features of the natural circulatorysystem. Generally, any combination of the anatomical features of thenatural circulatory system may be included in the neonatal circulatorymodel 210. The particular combination of anatomical features utilized inthe neonatal circulatory model 210 of FIG. 4 will now be discussed ingreater detail.

As shown, the neonatal circulatory model 210 includes a right atrium212, a right ventricle 214, and a pulmonary artery 216. The neonatalcirculatory model 210 also includes respiratory features 218. In theillustrated embodiment, the respiratory features 218 include left andright lungs and a shunt. In some instances, characteristics of therespiratory features 218 are at least partially determined by arespiratory model, such as the respiratory model discussed below withrespect to FIG. 5. Referring again to FIG. 4, the neonatal circulatorymodel 210 also includes a pulmonary vein 220, a left atrium 222, a leftventricle 224, and an aorta 226. As shown, the aorta 226 is connected toa coronary artery 228 that leads to the right atrium 212. In someinstances, the aorta 226, the coronary artery 228, and the right atrium212 form a neonatal ischemia model. In general, the neonatal ischemiamodel is utilized to calculate characteristics of the components of theneonatal circulatory model, including such things as the contractilityof the four heart chambers, an ECG output of the neonatal model, and/orother ischemia-determinant characteristics of the neonatal circulatorymodel. In some instances, the neonatal model includes a neonatal cardiacdipole model based on these characteristics that generates 12-lead ECGwaves for the four heart chambers of the neonatal circulatory model andalso generates a contraction profile that includes timing andcontractility of each of the four heart chambers during a contraction.

The aorta 226 of the neonatal circulatory model 210 is also connected toa descending aorta 230 that leads to arterioles 232. The arterioles 232lead to fat 234, vein-rich tissue 236, and muscle 238. Generally, thefat 234, vein-rich tissue 236, and muscle 238 represent the tissues andorgans of the newborn and their corresponding effects on the neonatalcirculatory system. However, any combination and/or groupings of tissuesand organs of the newborn may be utilized in other embodiments toaccount for the effects of the tissues and organs of the newborn on theneonatal circulatory system. The fat 234, vein-rich tissue 236, andmuscle 238 lead to venules 242. The venules 242 lead to a vena cava 244that returns back to the right atrium 212. Generally, the right atrium212, right ventricle 214, pulmonary artery 216, respiratory features218, pulmonary vein 220, left atrium 222, left ventricle 224, aorta 226,coronary artery 228, descending aorta 230, arterioles 232, fat 234, veinrich tissue 236, muscle 238, venules 242, and vena cava 244 areinterconnected in a manner simulating the interactions of thecorresponding anatomical features of the natural circulatory system inorder to define the neonatal circulatory model 210.

Referring now to FIG. 5, shown therein is a diagrammatic schematic viewof a respiratory model 250 of the arrangement of FIG. 1 according to oneembodiment of the present disclosure. In some instances, the respiratorymodel 250 makes up at least a portion of the maternal model 104 and/orthe neonatal model 108 of the arrangement 100. It is understood that theactual parameters of the respiratory model 250 are tailored for theparticular model in which the respiratory model is to be used. Forexample, Table 4 below provides exemplary parameter values for differentmodels representative of patient simulators of varying age, gender,and/or physiological condition.

As shown, the respiratory model 250 includes a right lung 252, a leftlung 254, and dead space 256. In the illustrated embodiment the deadspace 256 includes a mouth 258, airway 260, and alveolar space 262. Aninformation exchange 264 conveys information relating to the right lung252 to a corresponding right lung 266 of a circulatory model, in someinstances. For example, the information exchange 264 sends informationrelated to the right lung 252 of the respiratory model 250 to thecirculatory model 110 of the maternal model 104 such that theinformation related to the right lung 252 is utilized as part ofcharacteristics of the respiratory features 118 of the circulatory model110. Similarly, an information exchange 268 conveys information relatingto the left lung 254 to a corresponding left lung 270 of a circulatorymodel, in some instances. For example, the information exchange 268sends information related to the left lung 254 of the respiratory model250 to the circulatory model 110 of the maternal model 104 such that theinformation related to the left lung 254 is utilized as part ofcharacteristics of the respiratory features 118 of the circulatory model110. The information exchanges 264, 268 are similarly used inconjunction with the respiratory features 218 of the neonatalcirculatory model 210 in some embodiments.

As a general matter, the components and/or the values associated withthe components of the circulatory models 110, 160, 210 and therespiratory model 250 are modifiable in order to simulate patients ofvarying age, gender, and/or pathologies. In short, the components andassociated values of the models can be varied to simulate a seeminglyinfinite number of patient conditions, each having different baselinephysiological characteristics. Accordingly, below are a series of tablesidentifying baseline physiological characteristics for seven differentsimulated patients: an average adult male, an average adult female, apregnant female, a fetus (38 weeks), a newborn (38 weeks), a 1 year old,and a 5 year old. It is understood that the baseline values identifiedin the tables are exemplary in nature and in no way limit the availablevalues for use with the present disclosure. To the contrary, it isexpected that the baseline values set forth in the tables will bemodified to define particular physiological characteristics associatedwith a desired patient scenario. Generally, the baseline values can bemodified to correspond to any value necessary to create the desiredpatient scenario.

Table 1 below sets forth some baseline values for general parameters ofthe circulatory models of the present disclosure. In particular, Table 1identifies the corresponding weight (kg), blood volume (ml), metabolismrate (ml/kg/min), heart rate (beats/min), blood pressure (mmHg), heartweight (g), baroreflex gain (index), and hematocrit (%) for each patientmodel.

TABLE 1 Table 1. Default Values for General Parameters of theCirculatory Models Female Male Female (Pregnant) Fetus Newborn 1year-old 5 year-old Weight(kg) 75 55 85 2.5 2.5 10 18.25 Blood 5000 47006750 225 225 900 1642.5 Volume(ml) Metabolism 3 3 3.5 7 11 8 5rate(ml/kg/min) Heart Rate 75 75 85 140 140 140 95 (beats/min) BloodPressure 120/81 113/74 105/60 53/37 66/48 88/64 99/66 (mmHg) Heart 300300 300 25 25 90 180 Weight(g) BaroReflex 2 2 2 0.5 2 2 2 GainHematocrit(%) 44 44 44 47 47 46 45

Table 2 below sets forth some baseline values for particularcompartments of the circulatory models of the present disclosure. Inparticular, Table 2 identifies the corresponding volume (ml) andelastance (mmHg/ml) for the various compartments and related anatomy ofthe circulatory models.

TABLE 2 Table 2. Default Values for Compartments of the CirculatoryModels Female Male Female (Pregnant) Fetus Newborn 1 year-old 5 year-oldLA-unstressed 30 28.2 30 1.35 1.35 5.4 9.855 volume LA-elastance 0.120.1149 0.12 2.1333 1.3333 0.3667 0.2374 LV-unstressed 30 28.2 30 1.351.35 5.4 9.855 volume LV-elastance 0.08 0.0766 0.08 1.4222 0.8889 0.24440.1583 Aorta- 28 26.32 37.8 1.26 1.26 5.04 9.198 unstressed volumeAorta- 3 2.8724 3 69.33333333 43.33333 11.9167 7.4201 elastanceIntrathoracic 112 105.28 156.8 5.04 5.04 20.16 36.792 Arteries-unstressed volume Intrathoracic 1.5 1.4362 1.5 34.6667 21.6667 5.95833.7100 Arteries- elastance Extrathoracic 370 347.8 518 16.65 16.65 66.6121.545 Arteries- unstressed volume Extrathoracic 1 0.9574 1 23.111114.4444 3.972222 2.4734 Arteries- elastance Muscle- 35 32.9 49 1.5751.575 6.3 11.4975 unstressed volume Muscle- 1.5 1.43617 1.5 34.666721.66667 5.9583 3.7100 elastance Vein Rich 139 130.66 194.6 6.255 6.25525.02 45.6615 Compartment- unstressed volume Vein Rich 0.37 0.3543 0.378.5511 5.344444 1.4697 0.9151446 Compartment- elastance Fat-unstressed11 10.34 15.4 0.495 0.495 1.98 3.6135 volume Fat-elastance 4.5 4.30854.5 104 65 17.875 11.1301 Extrathoracic 1036.58 974.3852 1451.211946.6461 46.6461 186.5844 340.5165 Veins- unstressed volume Extrathoracic0.017 0.0163 0.017 0.3929 0.2456 0.0675 0.0420 Veins- elastanceIntrathoracic 1216.855 1143.843 1703.5965 54.7585 54.7585 219.0338399.7367 Veins- unstressed volume Intrathoracic 0.018 0.017234 0.0180.416 0.26 0.0715 0.0445 Veins- elastance RA-unstressed 30 28.2 30 1.351.35 5.4 9.855 volume RA-elastance 0.1 0.0957 0.1 1.7778 1.1111 0.30560.1979

Table 3 below sets forth some baseline values for vessel resistance(mmHg*sec/ml) of the various compartments and related anatomy of thecirculatory models of the circulatory models of the present disclosure.

TABLE 3 Table 3. Default Values for Vessel Resistance of the CirculatoryModels Female Male Female (Pregnant) Fetus Newborn 1 year-old 5 year-oldLA-LV 0.0072 0.0069 0.0065 0.1287 0.0804 0.0221 0.0143 LV-Aorta 0.01720.0165 0.0165 0.3065 0.1916 0.0527 0.0341 Aorta- 0.0261 0.0250 0.02090.464 0.29 0.0798 0.0516 IntraAtery IntraArtery- 0.0486 0.0052 0.00480.1248 0.078 0.0215 0.0139 ExtraArtery ExtraArtery- 4.1 3.9255 3.2872.8889 45.5556 12.5278 8.1126 Muscle ExtraArtery- 1.14 1.0915 0.91220.2667 12.6667 3.4833 2.2557 VeinRich Comp ExtraArtery- 12.8 12.255310.24 227.5556 142.2222 39.1111 25.3272 Fat Muscle- 0.5 0.4787 0.48.8889 5.5556 1.5278 0.9893 ExtraVein VeinRich 0.14 0.1340 0.112 2.48891.5556 0.4278 0.2770 Comp- ExtraVein Fat- 1.55 1.4840 1.24 27.555617.2222 4.7361 3.0670 ExtraVein ExtraVein- 0.09 0.0862 0.072 1.6 1 0.2750.1781 IntraVein IntraVein-RA 0.003 0.0029 0.003 0.0533 0.0333 0.00920.0059 RA-RV 0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059 RV-PA 0.0030.0029 0.003 0.0533 0.0333 0.0092 0.0059 PA- 0.205 0.1963 0.1435 3.64442.2778 0.6264 0.4056 Rlung/Llung PA-Shunt 4 3.8298 2.8 35.5556 44.444412.2222 7.9148 flow Rlung/Llung- 0.06 0.0574 0.042 1.0667 0.6667 0.18330.1187 PV Shunt flow- 2.5 2.3936 1.75 NA 27.7778 7.6389 4.9467 PV PV-LA0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059 ExtraA-Ut NA NA 3.45 NANA NA NA UT-ExtraV NA NA 1.85 NA NA NA NA RA-LA NA NA NA 0.1 NA NA NAExtraArtery- NA NA NA 2 NA NA NA Pla Pla-IntraV NA NA NA 1.6 NA NA NAShunt-IntraA NA NA NA 35 NA NA NA

Table 4 below sets forth some baseline values for general parameters ofthe respiratory models of the present disclosure. In particular, Table 4identifies the corresponding residual volume (L), expiratory residualcapacity (L), tidal volume (L), airway resistance (normal, slightlyhigh, and high), anatomical dead space (L), and alveolar dead space (L)for each patient model. In some instances, airway resistance is measuredon a scale from 1-5, where 5 is normal airway resistance and smallervalues are indicative of increased airway resistance (e.g., 3 isindicative of slightly high airway resistance, 2 is indicative of highairway resistance, and 1 is indicative of extremely high airwayresistance). Other airway resistance scales are utilized in otherembodiments.

TABLE 4 Table 4. Default Values for Parameters of the Respiratory ModelsFemale Male Female (Pregnant) Fetus Newborn 1 year-old 5 year-oldResidual Volume(L) 1.2 1.2 2.2 NA 0.0375 0.15 0.27375 ExpiratoryResidual 1.1 1.1 1.1 NA 0.0375 0.15 0.27375 Capacity(L) Tidal Volume 0.50.46 0.6 NA 0.0175 0.07 0.12775 Airway Resistance normal normal NormalNA high High Slightly High Dead 0.15 0.15 0.15 NA 0.004725 0.01890.0344925 Space(Anatomic)(L) Dead 0.005 0.005 0.005 NA 0.000525 0.00210.0038325 Space(Alveolar)(L)

In use, the physiological models of the present disclosure are utilizedto control the physiological characteristics of patient simulators inorder to provide more realistic medical training environments. Forexample, in some instances, the pregnancy model 102 is utilized tosimulate one or more birthing scenarios where the physiologicalcharacteristics of the maternal model 104 and the fetal model 106 areconfigured to emulate the natural physiological characteristicsassociated with the one or more birthing scenarios. In that regard, thematernal model 104 is utilized to control aspects of a maternalsimulator and the fetal model 106 is utilized to control aspects of afetal simulator associated with the maternal simulator. In someinstances, the maternal model 104 includes one or more of a circulatorymodel, a respiratory model, an ischemia model, and a cardiac dipolemodel, while the fetal model includes one or more of a circulatorymodel, an ischemia model, and a central nervous system model.

In some embodiments, a controller coordinates parameters of the maternalmodel 104 and the fetal model 106 based on a desired physiologicalbirthing scenario. In some instances, the desired physiological birthingscenario is selectable by a user or instructor through a user interfaceassociated with the simulators. The desired physiological birthingscenario is selected from a plurality of scenarios, including maternalbleeding (varying amounts), maternal uterine rupture (varying sizes),maternal apnea, maternal VFib, maternal VTach, fetal bleeding (varyingamounts), fetal cord compression, normal labor, shoulder dystocia,breech presentation, cord prolapse, peripartum hemorrhage, amnioticfluid embolism, preterm labor, and/or other physiological birthingscenarios.

Aspects of some of these scenarios are discussed in greater detailbelow. In that regard, the effects of the physiological birthingscenarios on various vital signs will generally be discussed in relationto exemplary starting values for vital signs of the maternal and fetalmodels. For example, Table 5 below provides examples of such startingvalues. The values in Table 5 generally represent a starting point whereboth the mother and fetus are healthy. For sake of simplicity, thesehealthy starting values will be used to discuss the birthing scenariosbelow. However, it is understood that the maternal model and/or thefetal model may have other starting values (including valuesrepresentative of various pathologies). Further, the birthing scenariosdiscussed generally only include a single variable or condition.However, it is understood that the individual birthing scenariosdiscussed below may be combined, either concurrently or consecutively,with one or more other birthing scenarios such that multiple variablesor conditions are presented simultaneously or in series.

TABLE 5 Table 5. Exemplary Starting Values for Birthing ScenariosMaternal Model Properties Resp. Rate 20 Osat 96% EtCO2 32 ECG Sinus HR85 BP 112/67 Temperature 37 Fetal Model Properties Baseline HR 135 Variability Moderate Episodic Ch. Reactive Periodic Ch. None VariablesNone

Table 6 below describes the variations in the vital signs of thematernal and fetal models associated with maternal bleeding. Thematernal bleeding of Table 6 is intended to represent bleeding out oflocal tissue. For example, in the context of the maternal circulatorymodel 110 described above, bleeding would be out of one or more of thefat 134, vein-rich tissue 136, and muscle 138. The rate of bleeding canbe varied to simulate different levels of trauma. In that regard, Table7 below provides the corresponding values for the vital signs of thematernal and fetal models for a low rate of bleeding, while Table 8below provides the corresponding values for a high rate of bleeding.

TABLE 6 Table 6. Variations in Values for Maternal Bleeding MaternalModel Properties Resp. Rate Increase to take out additional CO2 that hasbuilt up Osat Decrease due to increased metabolism rate EtCO2 Increasedue to increased CO2 formation ECG Sinus -> Vfib (due to ischemia of theheart) HR Increase to compensate for decreased BP (BaroReflex) BPDecrease(blood loss) -> maintain (increased HR) -> 0 (ischemia)Temperature Increase (fever) -> decrease (death) Fetal Model PropertiesBaseline HR Decrease at 4^(th) min (delayed reaction, momOsat 80%)Variability Mod -> minimal -> absent Episodic Ch. Reactive -> nonePeriodic Ch. None -> late decel (poor exchange) -> none (no response)Variables None (no cord compression)

TABLE 7 Table 7. Time Lapse of Values for Maternal Bleeding (Low Rate)Parameter 30 s 1 min 2 min 3 min 4 min 5 min 6 min 7 min 8 min Resp.Rate 20 21 24 41 45 0 Osat 96 96 93 87 80 76 76 EtCO2 32 35 36 33 33 0Car. Rhy. Sinus Sinus Sinus Sinus Sinus Vfib Vfib Vfib Vfib HR 124 132135 135 137 0 0 0 0 BP 77/61 76/63 75/62 75/62 76/63 0 0 0 0 Temp 37.738.3 39.1 39.8 40.4 40.2 39 37 35 Baseline HR 135 140 140 140 125 111 8575 71 Var mod mod mod minimal minimal absent absent absent absent Spont.Ch reactive reactive reactive reactive reactive none none none nonePeriodic Ch none none none none none none late none none decels Var. Chnone none none none none none none none none

TABLE 8 Table 8. Time Lapse of Values for Maternal Bleeding (High Rate)Parameter 30 s 1 min 2 min 3 min 4 min 5 min 6 min RR 22 22 23 38 45 0Osat 96 97 94 86 80 78 EtCO2 31 30 37 34 33 0 Car. Rhy. Sinus SinusSinus Sinus Sinus Vfib HR 110 133 135 137 135 0 BP 86/62 74/61 75/6175/63 74/62 0/0 Temp 37.4 38 39 39.8 40.4 40.3 Baseline 135 135 140 125111 91 71 Var mod mod minimal minimal minimal absent absent Spont. Chreactive reactive reactive reactive non-reactive late decels late decelsPeriodic Ch none none none none none none none Var. Ch none none nonenone none none none

Table 9 below describes the variations in the vital signs of thematernal and fetal models associated with a uterine rupture. The uterinerupture of Table 9 is intended to represent bleeding out of the uterusof the maternal simulator. For example, in the context of the maternalcirculatory model 110 described above, bleeding would be out of theuterus 140. The rate of bleeding can be varied to simulate differentlevels of trauma. In that regard, Table 10 below provides thecorresponding values for the vital signs of the maternal and fetalmodels for a low rate of bleeding. There will be less latency of fetaldeterioration relative the maternal bleeding of local tissue discussedabove due to direct loss of uterine blood, which is the oxygen sourcefor the fetus.

TABLE 9 Table 9. Variations in Values for Uterine Rupture Maternal ModelProperties Resp. Rate Increase to take out additional CO2 that has builtup Osat Decrease due to increased metabolism rate EtCO2 Increase due toincreased CO2 formation ECG Sinus -> Vfib (due to ischemia of the heart)HR Increase to compensate decreased BP (BaroReflex) BP Decrease(bloodloss) -> maintain (increased HR) -> 0(ischemia) Temperature Increase(fever) -> decrease (death) Fetal Model Properties Baseline HR Decreaseat 10^(th) min (less delayed reaction, mom's Osat 93%) Variability Mod-> minimal -> absent Episodic Ch. Reactive -> none Periodic Ch. None ->late decel (poor exchange) -> none (no response) Variables None (no cordcompression)

TABLE 10 Table 10. Time Lapse of Values for Uterine Rupture (Low Rate)Parameter 30 s 1 min 2 min 3 min 4 min 5 min 6 min Resp. Rate 22 22 2121 21 21 23 Osat 96 96 96 96 95 96 95 EtCO2 32 31 31 31 31 34 32 Car.Rhy. Sinus Sinus Sinus Sinus Sinus Sinus Sinus HR 83 101 109 106 107 109108 BP 110/64 100/65 94/66 94/66 91/66 93/64 90/66 Temp 37 37 37 37 3737.3 37.3 Baseline HR 125 135 135 135 135 135 135 Var minimal mod modmod mod mod mod Spont. Ch reactive reactive reactive reactive reactivereactive reactive Periodic Ch none none none none none none none Var. Chnone none none none none none none Parameter 7 min 8 min 10 min 12 min14 min 16 min 18 min Resp. Rate 24 23 26 35 45 45 0 Osat 95 95 93 88 8375 0 EtCO2 30 31 30 30 28 30 0 Car. Rhy. Sinus Sinus Sinus Sinus SinusSinus Vfib HR 119 115 125 136 135 138 0 BP 86/65 91/66 81/64 77/64 77/6478/65 0 Temp 37.3 37.5 37.6 39.1 39.1 40.3 39.9 Baseline HR 135 135 13185 65 0 0 Var mod mod minimal absent absent subtle none Spont. Chreactive reactive reactive none none none none Periodic Ch none nonenone late decels late decels none none Var. Ch none none none none nonenone none

Table 11 below describes the variations in the vital signs of thematernal and fetal models associated with maternal apnea. Table 12 belowprovides the corresponding values for the vital signs of the maternaland fetal models for an exemplary embodiment of maternal apnea. Notethat the “??” values for Osat in Table 12 are representative of a Osatless than 60%.

TABLE 11 Table 11. Variations in Values for Maternal Apnea MaternalModel Properties Resp. Rate 0 (Apnea) Osat Quickly drop -> loss ofsignal (low reading) EtCO2 0 (Apnea) ECG Sinus -> Vfib (due to ischemiaof the heart) HR No change -> 0 BP Decrease(ischemia) -> 0(ischemia)Temperature No change Fetal Model Properties Baseline HR Decrease at3^(rd) min -> 0 at 8^(th) min Variability Mod -> minimal -> absentEpisodic Ch. Reactive -> none Periodic Ch. None -> late decel (poorexchange) -> none (no response) Variables None (no cord compression)

TABLE 12 Table 12. Time Lapse of Values for Maternal Apnea Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min 7 min 8 min RR 0 0 0 0 0 0 0 0 0Osat 97 88 ?? ?? ?? ?? ?? ?? ?? EtCO2 0 0 0 0 0 0 0 0 0 Car. Rhy. SinusSinus Sinus Sinus Sinus Sinus Sinus Sinus VFib HR 85 85 85 85 85 85 8585 0 BP 100/62 96/59 94/57 94/56 95/58 91/59 88/58 68/45 0 Temp 37 37 3737 37 37 37 37 37 Baseline 135 135 135 120 95 80 65 60 0 Var mod modminimal minimal absent absent absent absent none Spont. Ch reactivereactive reactive non none none none none none reactive Periodic Ch nonenone none none none late late late none decels decels decels Var. Chnone none none none none none none none none

Table 13 below describes the variations in the vital signs of thematernal and fetal models associated with maternal ventricularfibrillation (VFib). Table 14 below provides the corresponding valuesfor the vital signs of the maternal and fetal models for an exemplaryembodiment of maternal VFib. Notably, compared to maternal apneascenario discussed above, in the maternal VFib scenario, the maternalsimulator stops using oxygen. Accordingly, there's more oxygen supplyfor fetus and, therefore, the fetus is able to maintain good conditionfor longer (8 minutes in the illustrated embodiment).

TABLE 13 Table 13. Variations in Values for Maternal VFib Maternal ModelProperties Resp. Rate 0 (VFib) Osat Immediate loss of signal (HR = 0)EtCO2 0 (VFib) ECG VFib HR 0 (VFib) BP 0 (VFib) Temperature No changeFetal Model Properties Baseline HR Decrease at 9^(th) min -> 0 at13^(th) min Variability Mod -> minimal -> absent Episodic Ch. Reactive-> none Periodic Ch. None -> late decel (poor exchange) -> none (noresponse) Variables None (no cord compression)

TABLE 14 Table 14. Time Lapse of Values for Maternal VFib Parameter 30 s1 min 2 min 3 min 4 min 5 min 6 min 7 min RR 0 0 0 0 0 0 0 0 Osat ?? ???? ?? ?? ?? ?? ?? EtCO2 0 0 0 0 0 0 0 0 Car. Rhy. Vfib Vfib Vfib VfibVfib Vfib Vfib Vfib HR 0 0 0 0 0 0 0 0 BP 0 0 0 0 0 0 0 0 Temp 37 37 3737 37 37 37 37 Baseline 140 140 140 140 140 140 140 140 Var mod mod modmod mod mod mod mod Spont. Ch reactive reactive reactive reactivereactive reactive reactive reactive Periodic Ch none none none none nonenone none none Var. Ch none none none none none none none none 13 minParameter 8 min 9 min 10 min 11 min 12 min 13 min 15 s RR 0 0 0 0 0 0 0Osat ?? ?? ?? ?? ?? ?? ?? EtCO2 0 0 0 0 0 0 0 Car. Rhy. Vfib Vfib VfibVfib Vfib Vfib Vfib HR 0 0 0 0 0 0 0 BP 0 0 0 0 0 0 0 Temp 37 37 37 3737 37 37 Baseline 135 115 85 75 71 60 0 Var minimal minimal absentabsent absent absent none Spont. Ch reactive none none none none nonenone Periodic Ch none none late late late late none decels decels decelsdecels Var. Ch none none none none none none none

Table 15 below describes the variations in the vital signs of thematernal and fetal models associated with maternal ventriculartachycardia (VTach). Table 16 below provides the corresponding valuesfor the vital signs of the maternal and fetal models for an exemplaryembodiment of maternal VFib. The slight deterioration in fetal conditionis due to decreased maternal cardiac output which leads to decreasedblood flow to uterus.

TABLE 15 Table 15. Variations in Values for Maternal VTach MaternalModel Properties Resp. Rate Small variation (normal) Osat Smallvariation (normal) EtCO2 Small variation (normal) ECG Vtach HR 120 BP60/45 + Small variation (normal) Temperature No change Fetal ModelProperties Baseline HR Decrease at 11^(th) min -> maintain at 120 bpmVariability Mod -> minimal Episodic Ch. Reactive -> non reactivePeriodic Ch. None Variables None (no cord compression)

TABLE 16 Table 16. Time Lapse of Values for Maternal VTach Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min 7 min RR 20 19 18 20 21 21 21 21Osat 96 96 95 95 95 95 95 95 EtCO2 29 30 33 32 31 32 30 30 Car. Rhy.Vtach Vtach Vtach Vtach Vtach Vtach Vtach Vtach HR 120 120 120 120 120120 120 120 BP 59/45 61/45 70/52 62/46 61/45 68/51 60/45 60/45 Temp 3737 37 37 37 37 37 37 Baseline 135 135 135 135 135 135 135 135 Var modmod mod mod mod mod minimal mod Spont. Ch reactive reactive reactivereactive reactive reactive reactive reactive Periodic Ch none none nonenone none none none none Var. Ch none none none none none none none noneParameter 8 min 9 min 10 min 11 min 15 min 20 min 25 min RR 20 21 20 2121 20 20 Osat 94 94 95 94 95 94 95 EtCO2 32 30 32 31 31 32 32 Car. Rhy.Vtach Vtach Vtach Vtach Vtach Vtach Vtach HR 120 120 120 120 120 120 120BP 68/51 61/45 68/51 63/47 60/45 64/48 68/51 Temp 37 37 37 37 37 37 37Baseline 135 135 135 131 125 120 120 Var minimal minimal minimal minimalminimal minimal minimal Spont. Ch reactive reactive reactive reactivereactive non non reactive reactive Periodic Ch none none none none nonenone none Var. Ch none none none none none none none

Table 17 below describes the variations in the vital signs of the fetalmodel associated with fetal bleeding. The rate of bleeding can be variedto simulate different levels of trauma. In that regard, Table 18 belowprovides the corresponding values for the vital signs of the maternaland fetal models for a low rate of bleeding, while Table 19 belowprovides the corresponding values for a high rate of bleeding.

TABLE 17 Table 17. Variations in Values for Fetal Bleeding Fetal ModelProperties Baseline HR Immediate decrease -> 0 (Low rate at 8 min, Highrate at 3 min) Variability (Minimal) -> sinusoidal Episodic Ch.(Reactive) -> none Periodic Ch. None Variables None (no cordcompression)

TABLE 18 Table 18. Time Lapse of Values for Fetal Bleeding (Low Rate) 8min Parameter 30 s 1 min 2 min 3 min 4 min 5 min 6 min 7 min 8 min 4 sBaseline 120 131 135 135 140 135 120 80 60 0 Var sinusoidal Spont. Chnone Periodic Ch none Var. Ch none

TABLE 19 Table 19. Time Lapse of Values for Fetal Bleeding (High Rate) 1min 2 min 3 min Parameter 30 s 1 min 30 s 2 min 30 s 3 min 10 s Baseline120 115 85 75 65 0 Var sinusoidal Spont. Ch subtle Periodic Ch none Var.Ch none

At the end of a delivery or labor scenario, the parameters of the fetalmodel are transferred to the neonatal model. In some instances, thefetal model and the neonatal model are controlled by the same controlleror processor and, therefore, the transfer of parameters is performed bythe controller. In other instances, the fetal model and the neonatalmodel are controlled by separate controllers or processors such that theparameters of the fetal model must be communicated to the controller orprocessor for the neonatal model. Generally, the communication of theparameters may occur over any suitable communication protocol includingboth wired and wireless connections. In some instances, the parametersare communicated utilizing TCP/IP communication. In this manner, thefinal fetal parameters are the initial parameters of the neonate model.Additionally, in some instances the term (i.e., gestational age) of thefetus determines the lung maturity of the neonate. Accordingly, therespiratory model of the neonatal model is adjusted to match thedevelopment of the fetus. Further, the fetal central nervous systemmodel's final oxygen level at least partially determines the neuralactivity of the neonatal model in some instances. These and otherparameters of the fetal model affect the resulting characteristics ofthe neonatal model. In turn, the characteristics of the neonatal modeldirectly affect how the neonatal simulator responds to resuscitationefforts in post-birth simulations (e.g., the rate at which the neonatalsimulator responds to various resuscitation techniques).

As noted above, the relationship(s) between the various models and/orcompartments within the models are based on concurrent differentialequations in some embodiments. Below specific examples of equations usedto define the physiological relationships of the present disclosure. Itis understood that these equations are exemplary in nature and in no waylimit the specific relationships and/or equations that can be utilizedin the context of the physiological models the present disclosure.

With respect to the circulatory models, in some instances the followingrelationships are utilized:

Pressure=(Volume−Unstressed Volume)*Elastance

Flow Rate=(Pressure_(upflow)−Pressure_(downflow))/Resistance

With respect to the respiratory models, in some instances the followingrelationships are utilized for inspiration aspects of the respiratorymodels:

Normal/Asthma:

$R = {P_{\max}\# \frac{\left( {{- \frac{1}{3}} - \frac{t_{Insp}}{2} + \frac{t_{Insp}}{\left( {1 - ^{{- 3}t_{Insp}}} \right)}} \right)}{V_{tidal}}}$$P_{pleural} = {{{- P_{\max}}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Insp}}}} - P_{\min}}$$P_{transpulmonary} = {{{- P_{\max}}\# \frac{t_{respiration}}{t_{Insp}}} - P_{\min}}$P_(Alveolar) = P_(pleural) − P_(transpulmonary)f_(air) = −P_(Alveolar)/R

Emphysema:

$P_{pleural} = {{{- P_{\max}}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Insp}}}} - P_{\min}}$$P_{pleural} = {{{- P_{\max}}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Insp}}}} - P_{\min}}$$P_{transpulmonary} = {{{- P_{\max}}\# \frac{1 - ^{- t_{respiration}}}{1 - ^{- t_{Insp}}}} - P_{\min}}$P_(Alveolar) = P_(pleural) − P_(transpulmonary)f_(air) = −P_(Alveolar)/R

Fibrosis:

$R = {P_{\max}\# \frac{\left( {{- \frac{4}{3}} - \frac{t_{Insp}}{\left( {1 - ^{t_{Insp}}} \right)} + \frac{t_{Insp}}{\left( {1 - ^{{- 3}t_{Insp}}} \right)}} \right)}{V_{tidal}}}$$P_{pleural} = {{{- P_{\max}}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Insp}}}} - P_{\min}}$$P_{transpulmonary} = {{{- P_{\max}}\# \frac{1 - ^{t_{respiration}}}{1 - ^{t_{Insp}}}} - P_{\min}}$P_(Alveolar) = P_(pleural) − P_(transpulmonary)f_(air) = −P_(Alveolar)/R

With respect to the respiratory models, in some instances the followingrelationships are utilized for expiration aspects of the respiratorymodels:

Normal:

$R = {P_{\max}\# \frac{\left( {{- \frac{4}{3}} - \frac{t_{Exp}}{\left( {1 - ^{t_{Exp}}} \right)} + \frac{t_{Exp}}{\left( {1 - ^{{- 3}t_{Exp}}} \right)}} \right)}{V_{tidal}}}$$P_{pleural} = {{P_{\max}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Exp}}}} - P_{\min} - P_{\max}}$$P_{transpulmonary} = {{P_{\max}\# \frac{1 - ^{t_{respiration}}}{1 - ^{t_{Exp}}}} - P_{\min} - P_{\max}}$P_(Alveolar) = P_(pleural) − P_(transpulmonary)f_(air) = −P_(Alveolar)/R

Emphysema:

$P_{pleural} = {{{- P_{\max}}\# \frac{1 - ^{{- 3}t_{respiration}}}{1 - ^{{- 3}t_{Exp}}}} - P_{\min}}$$P_{transpulmonary} = {{{- P_{\max}}\# \frac{1 - ^{- t_{respiration}}}{1 - ^{- t_{Exp}}}} - P_{\min}}$P_(Alveolar) = P_(pleural) − P_(transpulmonary)f_(air) = −P_(Alveolar)/R

In the above equations related to the respiratory models, R=Resistance;P_(max)=Max Plueral Pressure; t_(Insp)=Inspiration Time;V_(tidal)=Intake Tidal Volume; P_(pleural)=Pleural Pressure;P_(min)=Min; P_(transpulmonary)=Transpulmonary Pressure;P_(Alveolar)=Alveolar Pressure; and f_(air)=air flow rate.

With respect to the gas exchanges utilized within the circulatory andrespiratory models, in some instances the relationships discussed beloware utilized. As a general matter, for the respiratory models theequations are based on dividing the airways into at least two segments,where one of the segments is dead space. Oxygen (O2) and carbon dioxide(CO2) are exchanged between the adjacent segments and then with thepulmonary capillaries (which are the right lung and left lungcompartments of the circulatory model, in some instances). The fractionsof oxygen and carbon dioxide are calculated and converted to partialpressures, such that the amount of gas exchanged with the capillaries isdefined by the following general equation: V_(exchange)=a (PartialPressure in Lungs−Partial Pressure in Capillaries), where “a” is aconstant. In some instances, for exchanges at the Alveoli-capillaryinterface it is assumed that Con_(O2cap)=Con_(O2alveoli) andCon_(CO2cap)=Con_(CO2alveoli). That is, it is assumed that CO2concentration in capillaries is equal to the O2 concentration in alveoliand, similarly, the CO2 concentration in capillaries is equal to the CO2concentration in alveoli. Similar equations are utilized for gasexchanges at other locations.

For example, for gas exchanges at the placenta-uterus interface thefollowing equations are utilized in some instances:

V _(gainO2)(ml/sec)=0.00315*(P _(utO2) −P _(plaO2))

V _(lostCO2)(ml/sec)=0.00255*(P _(plaCO2) −P _(utCO2))

In that regard, P_(utO2)=Uterus O2 Pressure; P_(plaO2)=Placenta O2Pressure; P_(utCO2)=Uterus CO2 Pressure; and P_(plaCO2)=Placenta CO2Pressure.

Referring now to FIG. 6, shown therein is a screen shot of userinterface 300 illustrating aspects of another embodiment of the presentdisclosure. In particular, the user interface 300 is an exemplaryembodiment of a user interface that facilitates control of one or moreof the physiological models described above. In that regard, the userinterface 300 is shown as being suitable for controlling at least thematernal and fetal models 104, 106 of the pregnancy model 102 describedabove. As a general matter, the user interface 300 allows a user tocontrol aspects of the physiological model(s) manually, if desired, orsimply allow the models to run automatically. For example, the user canchoose to operate FHR tracings in Manual, Auto or Birth mode. In thatregard, Birth mode is understood to represent a particular birthingscenario selected or created by the user. Further, the user has thefreedom to have parameters like “Baseline”, “Varability”, “Accel/DecelIntensity”, “Fetal Movement”, “Fetal O2 Level”, and/or other parametersof the models to be automatically controlled by the model or manuallycontrolled by the user.

As a general matter, when in manual mode the user is able to select ordefine the values for the various parameters. For example, in someinstances the user selects a particular value from a drop down menu,selection of buttons, or other visual display. Examples of suchavailable selections include but are not limited to: Fetal Movement:Auto, None, 0-1, 2-3, 4-5, >5; Fetal O2 Level: Auto, Normal, Poor, VeryPoor; Cord Compression: none, slight, severe; Placenta Previa None,Marginal, Partial, Total; and Abruptio Grade: 0, 1, 2, 3. In someinstances, the user defines a particular value by inputting a numericalvalue or other parameter defining term into an input field. It isunderstood that a user will have some parameters running in auto modewhile others are in manual mode in some instances. In other instances,the user will have the models running in either full auto mode or fullmanual mode.

Although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure and in some instances, some features of the presentdisclosure may be employed without a corresponding use of the otherfeatures. It is understood that such variations may be made in theforegoing without departing from the scope of the embodiment.Accordingly, it is appropriate that the appended claims be construedbroadly and in a manner consistent with the scope of the presentdisclosure.

What is claimed is:
 1. A system for teaching patient care, the systemcomprising: a maternal simulator comprising a maternal circulatorymodel, a maternal cardiac ischemia model, and a maternal respiratorymodel; a fetal simulator in communication with the maternal simulator,the fetal simulator comprising a fetal circulatory model, a fetalcardiac ischemia model, and a fetal central nervous system model; and acontroller in communication with the maternal simulator and the fetalsimulator, the controller coordinating parameters of the maternalcirculatory model, the maternal cardiac ischemia model, the maternalrespiratory model, the fetal circulatory model, the fetal cardiacischemia model, and the fetal central nervous system model to simulatephysiological characteristics of a natural mother and fetus.
 2. Thesystem of claim 1, wherein the maternal circulatory model is amulti-compartment circulatory model including a simulated uterus.
 3. Thesystem of claim 2, wherein the maternal circulatory model furtherincludes: a simulated right atrium, a simulated right ventricle, asimulated left atrium, and a simulated left ventricle.
 4. The system ofclaim 1, wherein the maternal ischemia model includes a simulated aortaand a simulated coronary artery.
 5. The system of claim 1, wherein thematernal respiratory model includes a simulated right lung and asimulated left lung.
 6. The system of claim 1, wherein fetal circulatorymodel is a multi-compartment circulatory model including a simulatedplacenta.
 7. The system of claim 6, wherein the fetal circulatory modelfurther includes at least: a simulated right atrium, a simulated rightventricle, a simulated left atrium, and a simulated left ventricle. 8.The system of claim 1, wherein the fetal ischemia model includes asimulated aorta and a simulated coronary artery.
 9. The system of claim1, wherein the maternal circulatory model and the fetal circulatorymodel are connected to one another.
 10. The system of claim 9, whereinthe maternal circulatory model includes a simulated uterus and the fetalcirculatory model includes a simulated placenta, the simulated placentabeing connected to the simulated uterus.
 11. The system of claim 1,wherein the maternal simulator includes a mechanism configured totranslate and rotate the fetal simulator relative to maternal simulatorto simulate a birth.
 12. The system of claim 1, wherein the controllerincludes a processor programmed to coordinate parameters of the maternalcirculatory model, the maternal cardiac ischemia model, the maternalrespiratory model, the fetal circulatory model, the fetal cardiacischemia model, and the fetal central nervous system model based on adesired physiological scenario.
 13. The system of claim 12, wherein thecontroller is positioned remote from the maternal simulator.
 14. Thesystem of claim 12, wherein the desired physiological scenario isselectable by a user through a user interface.
 15. The system of claim12, wherein the desired physiological scenario is selected from a groupconsisting of maternal bleeding, maternal uterine rupture, maternalapnea, maternal VFib, maternal VTach, fetal bleeding, and fetal cordcompression.
 16. The system of claim 1, wherein the maternal simulatorfurther includes a maternal cardiac dipole model.
 17. The system ofclaim 16, wherein the maternal cardiac dipole model generates 12-leadECG waves for four heart chambers of the maternal circulatory model. 18.The system of claim 17, wherein the maternal cardiac dipole modelfurther generates a contraction profile that includes timing andcontractility of each of the four heart chambers during a contraction.19. The system of claim 1, further comprising a neonatal simulator foruse in post birth situations, the neonatal simulator including aneonatal circulatory model, a neonatal cardiac ischemia model, and aneonatal respiratory model.
 20. The system of claim 19, wherein thecontroller is in communication with the neonatal simulator andconfigured to coordinate parameters of the neonatal circulatory model,the neonatal cardiac ischemia model, and the neonatal respiratory modelto simulate physiological characteristics of a newborn.
 21. The systemof claim 20, wherein the parameters of the neonatal circulatory modeland the neonatal cardiac ischemia model are at least partially basedupon the parameters of the fetal circulatory model and the fetal cardiacischemia model.
 22. An apparatus comprising: a patient simulatorcomprising: a patient body comprising one or more simulated bodyportions, the one or more simulated body portions including at least asimulated circulatory system and a simulated respiratory system; acontroller in communication with the patient simulator, the controllerconfigured to coordinate parameters of the simulated circulatory systemand the simulated respiratory system to simulate physiologicalcharacteristics associated with a desired physiological scenario, thecontroller determining the parameters of the simulated circulatorysystem and the simulated respiratory system for the desiredphysiological scenario based on a circulatory model and a respiratorymodel for the patient simulator.
 23. The apparatus of claim 22, whereinthe circulatory model is a multi-compartment circulatory model includingat least a simulated right atrium, a simulated right ventricle, asimulated left atrium, and a simulated left ventricle.
 24. The apparatusof claim 23, wherein the patient simulator is a maternal simulator andwherein the circulatory model includes a simulated uterus.
 25. Theapparatus of claim 22, wherein the respiratory model includes at least asimulated right lung and a simulated left lung.
 26. The apparatus ofclaim 22, wherein the controller determines the parameters of thesimulated circulatory system for the desired physiological scenario atleast partially based on an ischemia model for the patient simulator,the ischemia model including a simulated aorta and a simulated coronaryartery.
 27. The apparatus of claim 22, wherein the patient body is sizedand shaped to simulate a newborn.
 28. The apparatus of claim 27, whereinthe parameters of the simulated circulatory system are at leastpartially based on physiological characteristics of a fetus associatedwith the newborn.
 29. The apparatus of claim 28, wherein the fetusassociated with the newborn is the patient simulator prior to a birthingsimulation, and wherein the newborn is the patient simulator after thebirthing simulation.
 30. The apparatus of claim 22, wherein the patientsimulator is configured to generate 12-lead ECG waves and contractionprofiles for a heart of the simulated circulatory system, wherein thecontroller controls the 12-lead ECG waves and contraction profilesgenerated by the patient simulator.
 31. The apparatus of claim 30,wherein the controller determines values for the 12-lead ECG waves andthe contraction profiles based on a cardiac dipole model.
 32. A methodof teaching patient care, comprising: providing a maternal simulatorcomprising a simulated maternal circulatory system and a simulatedmaternal respiratory system; providing a fetal simulator for use withthe maternal simulator, the fetal simulator comprising a simulated fetalcirculatory system; controlling one or more parameters of the simulatedmaternal circulatory system and simulated maternal respiratory systembased on a maternal circulatory model, a maternal cardiac ischemiamodel, and a maternal respiratory model; and controlling one or moreparameters of the simulated fetal circulatory system based on a fetalcirculatory model, a fetal cardiac ischemia model, and a fetal centralnervous system model; wherein the parameters of the simulated maternalcirculatory system, the simulated maternal respiratory system, and thesimulated fetal circulatory system are coordinated to simulatephysiological characteristics of a natural mother and fetus for adesired physiological scenario.
 33. The method of claim 32, whereincontrolling the one or more parameters of the simulated maternalcirculatory system is further based on a maternal cardiac dipole model.34. The method of claim 32, wherein the one or more controlledparameters of the simulated maternal circulatory system includes one ormore of a maternal blood pressure, a maternal heart rate, and a maternalcardiac rhythm.
 35. The method of claim 32, wherein the one or morecontrolled parameters of the simulated fetal circulatory system includesa fetal heart rate.